Receiver

1. A receiver, comprising: a low noise amplifier (LNA) for receiving and amplifying a radio frequency (RF) signal; a passive mixer, coupled to the LNA without any AC coupling capacitance therebetween, for generating an intermediate frequency signal by down-converting the RF signal; a passive filter for filtering the intermediate frequency signal; a baseband processing block, including a transimpedance amplifier (TIA), for processing the filtered intermediate frequency signal; and a voltage controller for keeping a first node and a second node of a signal path to be around a common DC voltage, wherein the first node is located between an output terminal of the LNA and an input terminal of the passive mixer, and the second node is located between an output terminal of the passive mixer and an output terminal of the TIA.

2. The receiver according to claim 1 , wherein the voltage controller is arranged to apply the common DC voltage to the first node and the second node.

3. The receiver according to claim 1 , wherein the voltage controller is arranged to track one of voltages of the first node and the second node with the other.

4. The receiver according to claim 1 , wherein the voltage controller is arranged to keep the first node and the second node to be at the common DC voltage, so that there is no DC current flowing through the passive mixer.

5. The receiver according to claim 1 , wherein the passive mixer, the passive filter and the baseband processing block are arranged to provide low differential DC impedance so as to prevent a DC offset voltage generated at the output terminal of the LNA.

6. The receiver according to claim 1 , further comprising: a configurable block for reconfiguring an input impedance of the baseband processing block for different mobile telecommunication systems.

7. The receiver according to claim 1 , wherein the passive mixer is arranged to down-convert an in-band part of the RF signal to a passband of the passive filter, and down-convert an out-of-band part of the RF signal to a stopband of the passive filter.

8. The receiver according to claim 1 , wherein the passive filter is a resistor-capacitor (RC) type current-in current-out filter.

9. A receiver, comprising: a low noise amplifier (LNA) for receiving and amplifying a radio frequency (RF) signal; a passive mixer, coupled to the LNA without any AC coupling capacitance therebetween, for generating an intermediate frequency signal by down-converting the RF signal; a passive filter for filtering the intermediate frequency signal; a baseband processing block, including a transimpedance amplifier (TIA), for processing the filtered intermediate frequency signal; and a voltage controller for keeping a first node and a second node of a signal path to be around a common DC voltage; wherein the passive mixer is further arranged to up-convert an intermediate frequency voltage established at an input terminal of the passive filter into an RF band voltage at an input terminal of the passive mixer, and the passive filter is further arranged to suppress a voltage swing of the intermediate frequency voltage; wherein the first node is located between an output terminal of the LNA and an input terminal of the passive mixer, and the second node is located between an output terminal of the passive mixer and an output terminal of the TIA.

10. The receiver according to claim 9 , wherein the voltage controller is arranged to apply the common DC voltage to the first node and the second node.

11. The receiver according to claim 9 , wherein the voltage controller is arranged to track one of voltages of the first node and the second node with the other.

12. The receiver according to claim 9 , wherein the voltage controller is arranged to keep the first node and the second node to be at the common DC voltage, so that there is no DC current flowing through the passive mixer.

13. A receiver, comprising: a low noise amplifier (LNA) for receiving and amplifying a radio frequency (RF) signal; a passive mixer, coupled to the LNA without any AC coupling capacitance therebetween, for generating an intermediate frequency signal by down-converting the RF signal; a passive filter for filtering the intermediate frequency signal; and a baseband processing block, including a transimpedance amplifier (TIA), for processing the filtered intermediate frequency signal; wherein a first node, located between an output terminal of the LNA and an input terminal of the passive mixer, and a second node, located between an output terminal of the passive mixer and an output terminal of the TIA, are arranged to be kept at a common DC voltage, so that there is no DC current flowing through the passive mixer.

14. The receiver according to claim 13 , further comprising: a voltage controller for applying the common DC voltage to the first node and the second node.

15. The receiver according to claim 13 , further comprising: a voltage controller for tracking one of voltages of the first node and the second node with the other.

16. The receiver according to claim 13 , wherein the passive mixer, the passive filter and the baseband processing block are arranged to provide low differential DC impedance so as to prevent a DC offset voltage generated at the output terminal of the LNA.

17. The receiver according to claim 13 , further comprising: a configurable block for reconfiguring an input impedance of the baseband processing block for different mobile telecommunication systems.

18. The receiver according to claim 13 , wherein passive filter is an RC type current-in current-out filter.